Las Vegas PD tells us … Foxx is in the clear — at least criminally — because the statute of limitations of 3 years has long since run. The case was previously listed as an open investigation. As for a civil suit … nope — the statute of limitations has also run.

We broke the story … the woman accused Foxx of assaulting her 16 years ago at a party at his place, when he tried to get her to perform oral sex on him. She claims she refused … so he slapped her in the face with his penis.